Snapmirror question (32B and 64B AGGR / 7.X and 8.X)

We have a FAS3240 running OnTap 8.0.2P4 (64B Aggr) and was curious to know if we could snapmirror to an offsite FAS3140 running OnTap 7.3.2 (32B Aggr)?

We were told that we might be able to snapmirror vol to qtree (source to dest). I can't find any supporting documentation regarding that statement. We need to replicate a few volumes for a few months for DR purposes.